Spring set fluid release brake

ABSTRACT

A body means is fixed against rotation and has a plurality of friction plates operatively connected therewith to cooperate with friction plates secured to a rotatable member. A backplate means is secured to the body means. A pressure plate means is secured to a holding plate means, the pressure plate means and holding plate means being axially movable. A plurality of springs is positioned between the backplate means and the pressure plate means for moving the pressure plate means toward brake set position. An axially expansible pancake-type airtube is positioned between the backplate means and the holding plate means for moving the pressure plate means and the holding plate means in a brake release direction against the force of the springs.

United States Patent m 6 WA( 0062 135 28 58 ll 8 8 "l 2,698,676 1/1955Eason 2,417,855 3/1947 Barish... 2,541,707 2/1951 Primary Examiner-Duane A. Reger L e T S a h m 5 w.m h wk Jwn r 0 m N m a V D. m A .1 2 .l7 2 1.. i

Lyman [22] Filed Jan. 7, 1969 [45] Patented 1971 Anorneys-wayland D.Keith and Roy W. Butrum [54] SPRING SET FLUID RELEASE BRAKE ABSTRACT: Abody means is fixed against rotation and has a 2 Claims 9 Drawing Figsplurality of friction plates operatively connected therewith tocooperate with friction plates secured to a rotatable member.

A backplate means is secured to the body means. A pressure plate meansis secured to a holding plate means, the pressure plate means andholding plate means being axially movable. A plurality of springs ispositioned between the backplate means and the pressure plate means formoving the pressure plate means toward brake set position. An axiallyexpansible pancake-type airtube is positioned between the backplatemeans [56] References Cited and the holding plate means for moving thepressure plate UNITED STATES PATENTS 2/1952Danlyetal....................

means and the holding plate means in a brake release direction againstthe force of the springs.

PATENTED AUG! 7 l9?! SHEET 1 OF a FIG. I

JACK W. MOSS INVENTOR.

HIS AGENT PATENIED we] 7 I9?! SHEEI 2 OF 4 FIG. 2

INVENTOR.

m AGENT JACK W. MOS S FlG. 3/-\ FIG. 5

PATENTED AUG] 7 ran SHEET 3 OF a FIG. 4

9 f mm 6 r0 2 AHIMJ 4 4 7 7 6 E g fiwm/w 2/ J 7 A 8 Mm & Kw e 7 MR4 a r4 2 n z w Hi 3 [yr A JACK W. M 038 INVENTOR.

HIS AGEN PATENTED AUG! 7 197:

SHEET l9, BF 4 FIG.

FIG, 7

JACK W. MOSS INVENTOR.

SPRING SET FLUID RELEASE BRAKE BACKGROUND OF THE INVENTION The presentinvention relates to a so-called multiple-disctype brake which is set bysuitable springs and released by fluid pressure.

It is desirable to provide a brake of this type which is as compact aspossible and which is furthermore simple and inexpensive in constructionyet sturdy and reliable in operation and requiring a minimum ofmaintenance.

It is difficult to provide an effective fluid operating means in a brakeincorporating the above-mentioned desired design characteristics. Priorart brakes of this type have either employed rather bulky and expensivefluid motors for releasing the brake or constructions which do notprovide satisfactory operating characteristics.

SUMMARY. OF THE INVENTION A body means is fixed against rotation and hasa first plurality of friction plates operatively connected therewith. Arotatable means has a second plurality of friction plates operativelyconnected therewith which cooperate with the first plurality of frictionplates in a well-known manner.

A backplate means is secured to the body means, and a pressure platemeans which is secured to a holding plate means is mounted for axialmovement with respect to the backplate means. A plurality of springs aredisposed between and in engagement with the backplate means and thepressure plate means for normally urging the pressure plate means in adirection to set the brake.

A fluid operating means is positioned between the backplate means andthe holding plate means for moving the pressure plate means and theholding plate means in a brake release direction. The fluid operatingmeans comprises an axially expansible flexible diaphragm which is apancake-type airtube. With this construction, the fluid operating meansprovides an effective fluid pressure area over the entire diametricalarea of the airtube thereby affording an enlarged area as compared withan annular tube, for example, and ensuring maximum efficiency ofoperation when moving the brake in a release direction.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevation ofa brakeaccording to the present invention;

FIG. 2 is an end view, on a reduced scale, of the brake shown in FIG. 1;

FIG. 3 is a sectional view on a reduced scale taken substantially alongline 3-3 of FIG. 1 looking in the direction of the arrows;

FIG. 3A is a sectional view taken on the line 3A-3A of FIG. 3, lookingin the direction indicated by the arrows, and on the same scale as FIG.3;

FIG. 4 is a sectional view on an enlarged scale taken substantiallyalong line 4-4 of FIG. 2 looking in the direction of the arrows;

FIG. 5 is an elevation of the backplate means of the brake, on a reducedscale;

FIG. 6 is a sectional view taken substantially along line 66 of FIG. 5looking in the direction of the arrows;

FIG. 7 is an elevation of the pressure plate means of the brake, on areduced scale; and

FIG. 8 is a sectional view taken substantially along line 8-8 of FIG. 7looking in the direction of the arrows.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawingswherein like reference characters designate corresponding partsthroughout the several views, as seen most clearly in FIGS. 1 and 4, thebrake includes a body means indicated generally by reference numeral l0and including a substantially cylindrical wall portion 12 and an annularrear wall 13 having a peripherally extending radially, outwardlydirected flange 14 formed integral therewith. A plurality of holes 16are formed through flange 14, at spaced points therearound, forreceiving bolts or the like whereby the body can be affixed to anysuitable supporting structure so that the body means is held againstrotation.

The wall 12 of the body means has a plurality of elongated slots 18formed therethrough, these slots enabling air to circulate within thebrake so as to cool the brake during operation. The forward end of thebody means is provided with a plurality of circumferentially spacedtapped holes 20 in the end edge thereof, for a purpose hereinafterdescribed.

A first plurality of generally annular friction plates 22, ofconventional construction, are provided, these friction plates havingpassages 24 formed therein to permit air to circulate through the platesto cool them during operation. The outer peripheries of friction plates22 have external teeth 26 formed thereon which engage longitudinallyextending internal teeth 28 formed on the inner periphery of wall 12 ofthe body means, whereby friction plates 22 are adapted to movelongitudinally with respect to the body means but are held againrotation with respect thereto.

A generally cylindrical hub means 30 has a central bore 31 extendinglongitudinally therethrough.- A longitudinally extending radiallyinwardly directed key 32 is provided within the hub, and a radiallyextending threaded hole 34 is adapted to receive a set screw or thelike. The hub is adapted to be drivingly interconnected with a suitablerotating member such as a shaft or the like, through the intermediary ofthe key 32 and a screw threaded within hole 34 in a well-known manner.

The outer periphery of the hub means is provided with longitudinallyextending external teeth 36 which are adapted to engage internal teeth38 formed on the inner peripheries of a second plurality of annularfriction plates 40. Friction plates 40 have passages 42 formed thereinto permit air to circulate through the plates to cool them duringoperation. The second plurality of friction plates 40 are nested betweenadjacent ones of said first plurality of said friction plates 22 so asto provide a conventional multiple-disc-type arrangement.

Referring now to FIGS. 5 and 6 of the drawings, the backplate of thebrake includes a central flat disclike portion 50, having a plurality ofgenerally cylindrical spaced holes 52 formed in one surface thereof,these holes each being adapted to receive one end of a compressionspring as hereinafter described. A plurality of spaced stop portions 54are formed integral with portion 50 and extend longitudinally of thebackplate, these stop portions serve to interengage the pressure platehereinafter described. These stop portions are of generally arcuateconfiguration and are illustrated as being six in number, as seen mostclearly in FIG. 5.

A plurality of bosses 56, also shown as being six in number, extendradially outwardly of the central disclike portion 50 of the backplate,each of these bosses also extending longitudinally of the backplate andincluding a relatively thin arcuate portion 58 extending beyond theremainder of the associated boss. Each of these bosses has a hole 60formed therethrough, these holes 60 being aligned with the holes 20formed in the end of the body means 10. A bolt 64 extends through eachof holes 60 formed in the bosses on the backplate and is threaded intoone of the tapped holes 20 formed in the body means whereby thebackplate is fixedly secured to the body means.

As seen in FIG. 5, it will be noted that a plurality of recesses 64 aredefined between adjacent ones of the bosses 56 on the backplate, each ofthese recesses being disposed radially outwardly of one of the stopportions 54.

Referring now to FIGS. 7 and 8, the pressure plate of the brake includesa flat disclike central portion having a plurality of generallycylindrical holes 72 formed in one face thereof. These holes 72 areidentically spaced to the holes 52 formed in the backplate and each holeis adapted to receive the end of one of the compression springs disposedbetween these two plates. When the backplate and pressure plate aredisposed in assembled relationship with respect to one another, aplurality of compression springs 74 are provided as seen most clearly inFIG. 4, the opposite ends of these springs being positioned within theaforementioned holes in the plates, the springs serving to urge thepressure plate away from the backplate and toward brake set position.

The face of the pressure plate, opposite to that within which the holes72 are formed, is provided with a plurality of spaced radially directedlugs 76 each one of which defines a longitudinally extending shoulder78. These lugs 76 are adapted to engage the adjacent friction disc 22,the shoulders 78 fitting within the inner periphery of the associatedfriction disc.

A plurality of spaced bosses 80, shown as being six in number, extendradially outwardly of the central disclike portion 70 of the pressureplate, these bosses also extending longitudinally of the pressure plate.Each of these bosses has an arcuate cutout 82 formed therein, and atapped hole 84 is provided in each boss. The bosses are spaced from oneanother so as to define a plurality of recesses 86 between adjacent onesof the bosses.

In the assembled relationship of the backplate and the pressure plate,as seen in FIG. 4, the bosses formed on the backplate fit within therecesses provided on the pressure plate, while the bosses formed on thepressure plate fit within the recesses provided at the outer peripheryof the backplate. This arrangement enables the pressure plate to movelongitudinally with respect to the backplate.

As seen most clearly in FIGS. 2, 3 and 4, a holding plate 90 includes alongitudinally extending peripheral flange 92 having a first pluralityof counterbored holes 94 formed therethrough. Bolts 96 extend throughthese counterbored holes and into the tapped holes 84 formed in theaforementioned pressure plate whereby the holding plate and the pressureplate are secured to one another and are adapted to move as a unit.

As seen in FIG. 3, longitudinally extending arcuate portions 98 areformed on the holding plate integral with flange 92 at spaced portionsdisposed radially inwardly of the counterbored holes 94. These spacedportions 98 are separated from one another by milled out radiallyextending recesses 100. Cylindrical holes 102 are formed through theholding plate at the central part of each of the recesses 100, holes 102providing access openings for gaining access to the aforementioned bolts64 whereby the bolts 64 may be threaded into and out of operativeposition through the openings 102 if so desired.

The holding plate 90 is provided with a longitudinally extendingcounterbored hole 110 formed through the central part thereof, and theinner face thereofis provided with a pair of diametrically oppositegenerally cylindrical holes 112 for a purpose hereinafter described.

A fluid operating means is interposed between the backplate and theholding plate The fluid operating means in the present inventioncomprises an axially expansible flexible diaphragm in the form ofapancake-type airtube 120, formed of a suitable elastomeric material suchas rubber or the like. This airtube is provided with a pair of disclikelugs 122 which snugly fit within the holes 112 of the holding platewhereby the airtube is properly supported and held in the operativeposition illustrated.

An annular O-ring 124 is supported in the outer part of the interior ofthe airtube so as to reduce the volume thereof. Shallow grooves 126 aredisposed 90 apart on the bottom of the airtube.

The open end ofthe airtube is fixedly secured to an annular member 128which in turn is sealed by an annular seal 130 with respect to a fitting134 which is adapted to be suitably interconnected with any source offluid pressure such as air or the like. A variable pressure controlvalve (not shown) ofconventional construction may be employed forcontrolling the air pressure admitted into the interior ofthe airtube.

In the absence of the air pressure within the airtube, springs 74 willurge the pressure plate means to the left as seen in FIG. 4, therebycausing the first and second plurality of friction plates to tightlyengage one another and setting the brake. On

the other hand, when pressure is applied to the interior of the airtube,the holding plate and the pressure plate will be caused to move to theright against the force of the springs to thereby release the brake.Stop portions 54, on the backplate, will engage the pressure plate,after a predetermined amount of movement in the release directions, soas to limit the movement of the pressure plate toward the backplate. Bycontrolling the amount of air pressure within the airtube, the brake maybe engaged to any degree desired.

It is apparent that the brake arrangement of the present invention isvery compact and simple and inexpensive in construction, and yet, at thesame time, is quite sturdy and reliable in operation and requires aminimum of maintenance. The airtube has an effective fluid pressure areaover the entire diametrical area of the tube and enables the brake to beoperated in a most effieient manner.

As this invention may be embodied in several forms without departingfrom the spirit or essential characteristics thereof, the presentembodiment is therefore illustrative and not restrictive, and since thescope of the invention is defined by the appended claims, all changesthat fall within the metes and bounds of the claims or that form theirfunctional as well as conjointly cooperative equivalents are thereforeintended to be embraced by those claims.

What I claim is:

1. A spring set, fluid pressure release brake which comprises;

a. a hollow body means having circumferentially spaced teeth around theinterior thereof, 1. said hollow body means being fixed againstrotation,

b. a plurality of friction plates, each having circumferentially spacedteeth fitted within said hollow, toothed body means in relativelynonrotatable, driving relation but being axially slidable with respectthereto,

c. a backplate fixedly secured to said body means,

I. said backplate having a plurality of bosses formed thereon,

2. said backplate having a plurality of recesses defined between saidbosses,

d. a pressure plate mounted for axial movement relative to saidbackplate, said pressure plate and said backplate being nonrotatablerelative to each other,

. said pressure plate having a plurality of spaced-apart bosses formedthereon,

2. said pressure plate having a plurality of recesses defined betweensaid bosses,

. the bosses of said pressure plate being received within the recessesdefined in said backplate to permit longitudinal movement therebetweenbut to prevent relative rotational movement therebetween,

e. a plurality of compression springs positioned intermediate saidbackplate and said pressure plate and being in engaged relationtherewith to normally urge said pressure plate into engagement with atleast one of said friction plates to selectively hold said body meansand said friction plates in braking relation,

. a holding plate, having a cavity formed therein, fixedly secured tosaid pressure plate for rotation therewith,

g. a fluid-pressure-operated tube, forming a closed envelope, fittedwithin said cavity in said holding plate and being in bearing relationwith said backplate and said holding plate to effect relative axialmovement therebetween, upon introduction of fluid pressure into saidclosed envelope to effect the disengagement between said pressure plateand at least one said friction plate to release said brake against thepressure of said compression springs.

2. A spring set, fluid pressure release brake, as defined in claim Iwherein a. said backplate has a plurality of spaced-apart stop portionsformed thereon for engaging said pressure plate to limit the axialmovement of said pressure plate in a brake release direction.

1. A spring set, fluid pressure release brake which comprises; a. ahollow body means having circumferentially spaced teeth around theinterior thereof,
 1. said hollow body means being fixed againstrotation, b. a plurality of friction plates, each havingcircumferentially spaced teeth fitted within said hollow, toothed bodymeans in relatively nonrotatable, driving relation but being axiallyslidable with respect thereto, c. a backplate fixedly secured to saidbody means,
 1. said backplate having a plurality of bosses formedthereon,
 2. said backplate having a plurality of recesses definedbetween said bosses, d. a pressure plate mounted for axial movementrelative to said backplate, said pressure plate and said backplate beingnonrotatable relative to each other,
 1. said pressure plate having aplurality of spaced-apart bosses formed thereon,
 2. said pressure platehaving a plurality of recesses defined between said bosses,
 3. thebosses of said pressure plate being received within the recesses definedin said backplate to permit longitudinal movement therebetween but toprevent relative rotational movement therebetween, E. a plurality ofcompression springs positioned intermediate said backplate and saidpressure plate and being in engaged relation therewith to normally urgesaid pressure plate into engagement with at least one of said frictionplates to selectively hold said body means and said friction plates inbraking relation, f. a holding plate, having a cavity formed therein,fixedly secured to said pressure plate for rotation therewith, g. afluid-pressure-operated tube, forming a closed envelope, fitted withinsaid cavity in said holding plate and being in bearing relation withsaid backplate and said holding plate to effect relative axial movementtherebetween, upon introduction of fluid pressure into said closedenvelope to effect the disengagement between said pressure plate and atleast one said friction plate to release said brake against the pressureof said compression springs.
 2. said backplate having a plurality ofrecesses defined between said bosses, d. a pressure plate mounted foraxial movement relative to said backplate, said pressure plate and saidbackplate being nonrotatable relative to each other,
 2. said pressureplate having a plurality of recesses defined between said bosses,
 2. Aspring set, fluid pressure release brake, as defined in claim 1 whereina. said backplate has a plurality of spaced-apart stop portions formedthereon for engaging said pressure plate to limit the axial movement ofsaid pressure plate in a brake release direction.
 3. the bosses of saidpressure plate being received within the recesses defined in saidbackplate to permit longitudinal movement therebetween but to preventrelative rotational movement therebetween, E. a plurality of compressionsprings positioned intermediate said backplate and said pressure plateand being in engaged relation therewith to normally urge said pressureplate into engagement with at least one of said friction plates toselectively hold said body means and said friction plates in brakingrelation, f. a holding plate, having a cavity formed therein, fixedlysecured to said pressure plate for rotation therewith, g. afluid-pressure-operated tube, forming a closed envelope, fitted withinsaid cavity in said holding plate and being in bearing relation withsaid backplate and said holding plate to effect relative axial movementtherebetween, upon introduction of fluid pressure into said closedenvelope to effect the disengagement between said pressure plate and atleast one said friction plate to release said brake against the pressureof said compression springs.